Friday, August 08, 2008

Neandertal DNA Mapped

Researchers have mapped the mitochondrial DNA of a Neandertal using a bone from a specimen thought to be 38 000 years old. The Australian.com story states:

"For the first time, we've built a sequence from ancient DNA that is essentially without error," said Richard Green of Max-Planck Institute for Evolutionary Anthropology in Germany.

Research suggests that the last common ancestor of Neanderthals and humans lived about 660,000 years ago.

The Neanderthal mitochondrial genome presented in the study is a useful forerunner for the sequencing of the complete Neanderthal nuclear genome, the researchers said, adding that this project is already well underway.

The story does go on to say that the precise relationship between Neandertals and modern humans is not known. I will have to find out what Milford Wolpoff and Dave Frayer are saying about this, since it pokes yet another hole in the Neandertal/modern human continuity argument for central and western Europe.

3 comments:

  1. Wolpoff1:30 PM

    I (Wolpoff) can answer that. Nothing new, mtDNA is under selection and its been known for a while that there was a recent bottleneck that reduced its variability.

    Wolpoff, M.H., J. Hawks, and R. Caspari 2000 Multiregional, Not Multiple Origins. American Journal of Physical Anthropology 112(1):129-136.

    This was not a population size bottleneck, because nuclear genes were not affected. So there was selection on the mtDNA. The point is that it does not address the question of whether there was Neandertal ancestry for later Europeans (as noted in the Cell commentary), only nuclear DNA does, and so far the answer there seems to be yes.

    Hawks, J, Cochran, G, Harpending, HC, and Lahn, BT. 2008 A genetic legacy from archaic Homo. Trends in Genetics 24(1):19-23.

    I can send the references to an e-mail address.

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  2. That would be great. Please send to kidderjh@ornl.gov. Milford is quite correct. Selection does act on mitochondrial DNA and there is stochastic loss of lineages. This study does not address later Neandertals and their relationship to modern humans. As we have seen, there is evidence of separate lineages coming back together. This is documented for the ape/human split, and there is by no means concrete evidence that the early moderns in Europe and the Wurm Neadertals were separate species.

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  3. Wolpoff wrote

    This was not a population size bottleneck, because nuclear genes were not affected.

    This is probably a rabbit trail question from a genetics layman, but what other sort of bottleneck is there? Heavy selection-induced variability squeeze?

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